Measuring method of circular shape, measuring method of cylindrical shape, and measuring apparatus of cylindrical shape

摘要

The present invention aims at providing a measuring method of making loads of measurement few, making each measured value extremely exact, and efficiently reducing the number of measurement points, in cylindrical dimension measurement, and in particular, the measurement of a circumferential shape. In a measuring method of a shape of a cross-sectional circle which is orthogonal to an axis of a cylinder, the present invention is characterized by having a step of calculating distances between a reference point and points on a circumference on the basis of change of the distances of at least three predetermined points on the circumference of the cross-sectional circle to the reference point set in the cross-sectional circle by the rotation of the cylinder, and specifying the shape of the cross-sectional circle.